Gas discharge panel and operating system

ABSTRACT

A self-scanning gas discharge device using three electrode systems in which the electrodes of the cathode system and those of the auxiliary anode system extend in the same direction and are interconnected in groups for obtaining as few as possible crossing interconnections between the electrodes.

United States Patent Van Gelder et a1.

GAS DISCHARGE PANEL AND OPERATING SYSTEM Inventors: Zeger Van Gelder; Mathieu Martinus Maria Petrus Mattheij, both of Emmasingel, Eindhoven,

Netherlands Assignee: U.S. Philips Corporation, New

York, NY.

Filed: Oct. 23, 1973 Appl. No.: 408,401,

Foreign Application Priority Data Oct. 31, 1972 Netherlands 7214702 US. Cl. 315/169 TV, 313/201, 313/214,

315/168, 340/324 M Int. Cl. I-I05b 37/00 Field of Search 315/846, 169 R, 169 TV, 315/168, 323; 340/324 M; 313/201, 220, 214, 217

[ Feb. 11, 1975 [56] References Cited UNITED STATES PATENTS 3,701,924 10/1972 Glaser 315/846 3,725,731 4/1973 Kazan 315/169 R 3,778,673 12/1973 Eisenberg et al. 315/169 R 3,789,265 1/1974 Holz et a1. 315/169 TV Primary Examiner-John Kominski Assistant Examiner-E. R. LaRoche I Attorney, Agent, or Firm-Frank R. Trifari; Bernard Franzblau [57 ABSTRACT A self-scanning gas discharge device using three electrode systems in which the electrodes of the cathode system and those of the auxiliary anode systemextend in the same direction and are interconnected in groups for obtaining as few as possible crossing interconnections between the electrodes.

8 Claims, 4 Drawing Figures A'lfll as sa -e es s7 71 PATENTEB H975 3,865 090 SHEET 10F 4 Fig. 1

P/UENTEB FEBI 1 i975 saw u or A GAS DISCHARGE PANEL AND OPERATING SYSTEM The invention relates to a gas discharge device comprising a gas discharge panel having at least a cathode system, an auxiliary anode system and an anode system in which at least part of the electrodes of one of these systems crosses the electrodes of one of the other systems and in which at least part of-the electrodes of the cathode system is interconnected in groups, while each of a number of these groups is connected to a different output of a control circuit for automatically scanning the panel (self-scanning) by means of an auxiliary discharge extending every time along a subsequent electrode of the cathode system.

A gas discharge device of the kind described above is known from Electronics, 2-3-1970, pages l2l-l25 in which the anode of the cathode system cross those of the auxiliary anode system and of the anode system and are interconnected in three groups which are successively energized so that an auxiliary discharge can be displaced from cathode to cathode. All auxiliary anodes are connected to a positive voltage through a resistor. For larger panels the number of groups must be chosen to be more than three so as to provide a sufficient deionization period for the gas between two successive energizations of one and the same electrode. The number of crossings of connections to co-planar electrodes may then become undesirably large.

An object of the invention is to obviate this drawback.

A gas discharge device of the kind described in the preamble according to the invention is characterized in that at least part of the electrodes of the auxiliary anode system extends in the same direction as that of the groups of interconnected electrodes of the cathode system and are likewise interconnected in groups and that a number of these groups of the auxiliary anode system is each connected to a different output of a further control circuit while the said control circuits are mutually synchronized. I

By distributing the groups over two electrode systems the number of crossings per system can be greatly reduced and in some cases they can even be prevented completely. 4

The invention will now be described with reference to the drawing in which:

FIG. 1 diagrammatically shows a gas discharge device according to the invention.

FIG. 2 likewise diagrammatically shows a further embodiment of a gas discharge device according to the invention.

FIG. 3 shows a number of idealized voltage-time diagrams representing the waveforms occurring in the gas discharge device of FIG..1.

FIG. 4 likewise shows idealized voltage-time diagrams representing the waveforms occurring in the gas discharge device of FIG. 2.

In FIG. 1 a gas discharge panel 1 comprises a cathode system having a plurality of cathodes 3, 5, 7,9, 11, 13, and 17, an auxiliary anode system having a plurality of auxiliary anodes 19, 21, 23, 25, 27, 29, 31 and 33 and an anode system having a plurality of anodes 35, 37, 39, 41, 43, 45, 47 and 49. The cathodes, auxiliary anodes and anodes are positioned in planes mutually spaced apart while the planes accommodating the auxiliary anodes and cathodes are on the same side of the plane accommodating the anodes.

The cathode 3 and the auxiliary anode 19 are starting electrodes and are connected to outputs 51, 53, respectively, of a starter circuit 55.

A group of cathodes 5, l1 and 13 is interconnected and is connected to an output 57 ofa control circuit 59. A second group of cathodes 7, 9, 15 and 17 is interconnected and is furthermore connected to another output 61 of the control circuit 59.

A group of auxiliary anodes 21, 23, 29 and 31 is interconnected and is connected to an output 63 of a further control circuit 65 another output 67 of which is connected to a second group of interconnected auxiliary anodes 25, 27 and 33.

The starter circuit 55 and the control circuits 59 and 65 are mutually synchronized, which is denoted by connections 69 and 71.

The anodes 35, 37, 39, 41, 43, 45, 47 and 49 are each connected to an output of an anode control circuit 73 which has an input combination 75, 77, 79, 81 to which signals are applied which determine the image to be displayed. A clock signal input 83 is also connected to a clock signal input 85 of the control circuit 65. A clock signal for controlling the device is applied to input 83.

The operation of the circuit will now'be described with reference to the voltage-time diagram of FIG. 3.

In FIG. 3 a waveform 303 denotes the control voltage for the cathode 3, waveforms 305, 307, 309, 311, 313, 315 and 317 denote the control voltages for the cathodes 5, 7, 9, 11, 13, 15 and 17, respectively.

Waveforms 319, 321, 323, 325, 327, 329, 331 and 333 denote the control voltages for the auxiliary anodes 19; 21, 23, 25, 27, 29, 31 and 33, respectively.

During a period t to I, the auxiliary anode 19 has a positive voltage and the cathode 3 has a negative voltage as as result of which an auxiliary discharge occurs between this cathode 3 and auxiliary anode 19. In the auxiliary discharge the current is limited by a resistive layer 87 provided on the auxiliary anode 19. The other auxiliary anodes also have a resistive layer which will not be mentioned explicitly every time. The manner of current limitation in the auxiliary discharge may of course alternatively be-chose'n to be different;

The ignited condition of an auxiliary discharge between a cathode and an auxiliary anode is shown by a shaded area in FIG. 3. I

During the same period t, a large voltage difference occurs between the cathode 11 and the auxiliary anode 27 which is, however,-not sufficient to produce an auxiliary discharge because in a previous period no auxiliary dischargewas present between a juxtaposed cathode and an auxiliary anode.

During the next period t the voltage difference between the cathode 5 juxtaposed to the abovedescribed auxiliary discharge path or trajectory and the auxiliary anode 21 is large and an auxiliary discharge is produced between the latter electrodes under-the influence of the auxiliary discharge between the juxtaposed starter electrodes in the previous period. In the path between the starter electrodes 3 and 19 the auxiliary discharge is then extinguished while no auxiliary discharge can be produced between the electrodes 13 and 19 conveying a large voltage difference due to the absence of a neighbouring auxiliary discharge in the previous period.

It will be evident that in this manner the auxiliary discharge will successively be displaced to the electrode pairs 7-23, 9-25, 11-27, 13-29, -31 and 17-33 during the successive periods t 1,, r 2,, 1,, 1,, r 1 z, t and t t whereafter the entire cycle is repeated.

A large voltage difference occurs only every four periods at a given electrode pair of cathode and auxiliary anode so that the scanning rate can be chosen to be large without scanning being disturbed.

The interconnections of the electrode systems may be provided on either side of the panel as is diagrammatically shown in the Figure. Conductors crossing each other then need not be present in the electrode planes.

It will be evident that in addition to the connections to groups of electrodes as described above different groups may alternatively be chosen. For example, a first group of cathodes may have interconnected pairs of successive cathodes and a second group of cathodes may have interconnected pairs of successive cathodes located between pairs of the first group while the auxiliary anodes may then alternately be connected to a first group and to a second group. The frequency of the pulse signals at the auxiliary anodes is then double that at the cathodes. Alternatively, interconnected pairs of successive cathodes of a first group may be alternated by a single cathode of a second group while the same connection pattern of the auxiliary anodes is used with a displacement of one electrode instead ofthe total pattern relative to the cathode connection pattern. The required pulse patterns for the control then have unequal periods in which they are successively high and low and a high period is followed by two low periods, or conversely. The voltage patterns at the auxiliary anodes are displaced one period relative to those at the cathodes. The scanning periodicity covers only three periods in this case, thatis to say a large voltage. difference occurs every three periods'between a given cathode and a facing auxiliary anode.

In FIG. 2 the same reference numerals have been used for corresponding components.

The auxiliary anodes are interconnected in In groups and the cathodes are interconnected in n groupsin which in this example in 3 and n 2.

The groups of auxiliary anodes are connected to outputs 89, 91, 93 of the first control circuit 59 and the groups of interconnected cathodes are connected to outputs 95, 97 of the second control circuit 65.

FIG. 4 shows the voltage waveforms at the cathodes 3, 5, 7, 9, 11 and 13 by means of the reference numerals 403, 405, 407, 409, 411 and 413, respectively, and those at the auxiliary anodes 19, 21, 25, 27, 29 and. 31 by means of the reference numerals 419, 421, 425, 42 7, 429 565431, respectively.

In accordance with the operation of the circuit of FIG. 2 the auxiliary discharge is also taken over from period'to period by a subsequent cathode and auxiliary anode as is shown by the shaded area of the relevant parts of the voltage waveforms.

The periodicity is m x n in this system of interconnections, that is to say only after m x n periods a large voltage difference relative tothe auxiliary anode occurs at this auxiliary anode facing a given cathode. This scanning system is thus suitable for very large panels.

It will be evident that different values may alternativch be chosen for m and n in which there generally rimlk time w r. inth of sense also the cathodes may be connected to m groups and the auxiliary anodes may be connected to n groups. The voltage waveforms must be adapted accordingly.

The main discharge trajectory between the anode and the cathode has been left out of consideration in the foregoing because this is not important to an understanding of the invention. The main discharge may be ignited in known manner at a desired point of intersection of the auxiliary discharge with an anode when the relevant anode receives a sufficiently high voltage. The main discharge is extinguished when the auxiliary discharge is displaced to the next cathode-auxiliary anode pair.

What is claimed is:

1. A gas discharge device comprising a gas discharge panel including a matrix of gas cells, a cathode system including a plurality of parallel spaced electrodes, an auxiliary anode system and an anode system each comprising a plurality of parallel spaced electrodes in which at least part of the electrodes of one of these systems crosses the electrodes of one of the other systems, means for interconnecting at least part of the electrodes of the cathode system in groups, means for connecting each ofa number of these groups to a different output of a line scanning control circuit for automatically scanning the panel line by line by means of an auxiliary discharge extending'every time along a subsequent electrode of the cathode system, and wherein at least part of the electrodes of the auxiliary anode system extends in the same direction as that of the groups of interconnected electrodes of the cathodesystem and are likewise interconnected in at least two groups, means for connecting each of a number of these electrode groups of the auxiliary anode system to a different output of a second control circuit, a third control circuit'for selectively energizing the anode' electrodes, and means for mutually synchronizing said control circuits.

2. A gas discharge device as claimed in'claim 1, characterized in that the electrodes of each of the two electrode systems of interconnected electrodes'ar'e connected in two groups per electrode system.

3. A gas discharge device as claimed in claim 2, wherein the interconnecting points of the electrodes of the two groups of electrodes of an electrode system are located along opposite sides of the panel.

4. A gas discharge device as claimed in claim 1, characterized in that the electrodes of one of the electrode systems interconnected in groups are connected in' n groups and thosev of the other are connected in m groups in which in n z 2 and that a scanning rate obtained by the line scanning control circuit is the same from group to group for both electrode systemsf 5. A display device comprising a generally planar matrix of gas discharge cells, a cathode system including a plurality of parallel spaced cathode electrodes arranged adjacent said matrix of gas cells, an auxiliary anode system and an anode system comprising a plurality of parallel spaced auxiliary anode electrodes and a plurality of parallel spaced anode electrodes, respectively, arranged adjacent said matrix of gas cells such that the electrodes of one of these systems crosses the electrodes of one of the other systems to form a matrix, means for interconnecting at least some of the electrodes of the cathode system in separate groups, means for interconnecting at least some of the electrodes ofthe auxiliary anode system in separate groups. at least some of the electrodes of the auxiliary anode system extending parallel to at least some of the electrodes of the cathode system, line scanning control means with separate output terminals connected to respective groups of cathode electrodes for selectively energizing the groups of cathode electrodes in mutually exclusive time intervals to produce a line by line scanning of the gas cell matrix, a first control means with separate output terminals connected to respective groups of auxiliary anode electrodes for selectively energizing the groups of auxiliary anode electrodes, a second control means for selectively energizing the anode electrodes in accordance with electric signals representative of the information to be displayed, and means for synchronizing the operation of said first, second and line scanning control means.

6. A display device as claimed in claim 5 wherein the cathode, auxiliary anode and anode electrodes are arranged in separate parallel planes so that the planes of the auxiliary anode and cathode electrodes are on the same side of the plane of the anode electrodes.

7. A display device as claimed in claim 5 wherein the interconnecting points of one group of cathode electrodes is located along one side of the planar cell matrix and the interconnecting points of a second group of cathode electrodes is located along the opposite side of the planar cell matrix.

8. A display device as claimed in claim 7 wherein the interconnecting points of first and second interconnected groups of auxiliary anodes are likewise located along said one and said opposite sides of the planar cell matrix.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,866,090 Dated February 11, 1975 Inventor) ZEGER VAN GELDER ET AL It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

[- Col. 3, line 68, cancel the line and ihsert as follows: I

Q applies that m) n7/2 in which of course also the Signed and Sealed this twenty-first Day Of October 1975 [SEAL] Attest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer (mnmissimzer ofPatents and Trademarks 

1. A gas discharge deviCe comprising a gas discharge panel including a matrix of gas cells, a cathode system including a plurality of parallel spaced electrodes, an auxiliary anode system and an anode system each comprising a plurality of parallel spaced electrodes in which at least part of the electrodes of one of these systems crosses the electrodes of one of the other systems, means for interconnecting at least part of the electrodes of the cathode system in groups, means for connecting each of a number of these groups to a different output of a line scanning control circuit for automatically scanning the panel line by line by means of an auxiliary discharge extending every time along a subsequent electrode of the cathode system, and wherein at least part of the electrodes of the auxiliary anode system extends in the same direction as that of the groups of interconnected electrodes of the cathode system and are likewise interconnected in at least two groups, means for connecting each of a number of these electrode groups of the auxiliary anode system to a different output of a second control circuit, a third control circuit for selectively energizing the anode electrodes, and means for mutually synchronizing said control circuits.
 2. A gas discharge device as claimed in claim 1, characterized in that the electrodes of each of the two electrode systems of interconnected electrodes are connected in two groups per electrode system.
 3. A gas discharge device as claimed in claim 2, wherein the interconnecting points of the electrodes of the two groups of electrodes of an electrode system are located along opposite sides of the panel.
 4. A gas discharge device as claimed in claim 1, characterized in that the electrodes of one of the electrode systems interconnected in groups are connected in n groups and those of the other are connected in m groups in which m > n > or = 2 and that a scanning rate obtained by the line scanning control circuit is the same from group to group for both electrode systems.
 5. A display device comprising a generally planar matrix of gas discharge cells, a cathode system including a plurality of parallel spaced cathode electrodes arranged adjacent said matrix of gas cells, an auxiliary anode system and an anode system comprising a plurality of parallel spaced auxiliary anode electrodes and a plurality of parallel spaced anode electrodes, respectively, arranged adjacent said matrix of gas cells such that the electrodes of one of these systems crosses the electrodes of one of the other systems to form a matrix, means for interconnecting at least some of the electrodes of the cathode system in separate groups, means for interconnecting at least some of the electrodes of the auxiliary anode system in separate groups, at least some of the electrodes of the auxiliary anode system extending parallel to at least some of the electrodes of the cathode system, line scanning control means with separate output terminals connected to respective groups of cathode electrodes for selectively energizing the groups of cathode electrodes in mutually exclusive time intervals to produce a line by line scanning of the gas cell matrix, a first control means with separate output terminals connected to respective groups of auxiliary anode electrodes for selectively energizing the groups of auxiliary anode electrodes, a second control means for selectively energizing the anode electrodes in accordance with electric signals representative of the information to be displayed, and means for synchronizing the operation of said first, second and line scanning control means.
 6. A display device as claimed in claim 5 wherein the cathode, auxiliary anode and anode electrodes are arranged in separate parallel planes so that the planes of the auxiliary anode and cathode electrodes are on the same side of the plane of the anode electrodes.
 7. A display device as claimed in claim 5 wherein the interconnecting points of one group of cathode electrodes is located alOng one side of the planar cell matrix and the interconnecting points of a second group of cathode electrodes is located along the opposite side of the planar cell matrix.
 8. A display device as claimed in claim 7 wherein the interconnecting points of first and second interconnected groups of auxiliary anodes are likewise located along said one and said opposite sides of the planar cell matrix. 